Factor positive lookaheads better into find optimizations by stephentoub · Pull Request #112107

Factor positive lookaheads better into find optimizations by stephentoub · Pull Request #112107 · dotnet/runtime

A positive lookahead at the start of a pattern can be used for determining find optimizations even when the non-zero-width portions of the pattern aren't. This helps particularly in cases where the positive lookahead contains an anchor or a literal.

Also extends the existing alternation reduction optimization to factor out anchors that begin every branch of an alternation.

grendello added a commit to grendello/runtime that referenced this pull request

Feb 6, 2025

* main: (23 commits)
  add important remarks to NrbfDecoder (dotnet#111286)
  docs: fix spelling grammar and missing words in clr-code-guide.md (dotnet#112222)
  Consider type declaration order in MethodImpls (dotnet#111998)
  Add a feature flag to not use GVM in Linq Select (dotnet#109978)
  [cDAC] Implement ISOSDacInterface::GetMethodDescPtrFromIp (dotnet#110755)
  Restructure JSImport/JSExport generators to share more code and utilize more Microsoft.Interop.SourceGeneration shared code (dotnet#107769)
  Add more detailed explanations to control-flow RegexOpcode values (dotnet#112170)
  Add repo-specific condition to labeling workflows (dotnet#112169)
  Fix bad assembly when a nested exported type is marked via link.xml (dotnet#107945)
  Make `CalculateAssemblyAction` virtual. (dotnet#112154)
  JIT: Enable reusing profile-aware DFS trees between phases (dotnet#112198)
  Add support for LDAPTLS_CACERTDIR \ TrustedCertificateDirectory (dotnet#111877)
  JIT: Support custom `ClassLayout` instances with GC pointers in them (dotnet#112064)
  Factor positive lookaheads better into find optimizations (dotnet#112107)
  Add ImmutableCollectionsMarshal.AsMemory (dotnet#112177)
  [mono] ILStrip write directly to the output filestream (dotnet#112142)
  Allow the NativeAOT runtime pack to be specified as the ILC runtime package (dotnet#111876)
  JIT: some reworking for conditional escape analysis (dotnet#112194)
  Replace HELPER_METHOD_FRAME with DynamicHelperFrame in patchpoints (dotnet#112025)
  [Android] Decouple runtime initialization and entry point execution for Android sample (dotnet#111742)
  ...